The draft air pollution plans were due to be published on 24 April. Last week the government lodged an application to delay their release until after the general election, due to purdah rules. Purdah prevents announcements during pre-election periods that may have political implications. However, on Thursday the judge ruled that as a matter of public health, air pollution should be exempt from purdah conventions.

The air quality plans must set out the government’s approach to reducing nitrogen dioxide levels below EU limits in the shortest possible time.

This is the latest in a long-running legal action brought by the NGO ClientEarth, that dates back to 2011. In November 2016, the High Court ruled that government plans to address poor air quality do not do enough to meet the UK’s obligations under EU law.

Under the Air Quality Directive 2008, the UK government is obliged to take steps to mitigate the harmful effects of air pollution (including from nitrogen dioxide emissions) by setting standards for, and taking steps to assess and manage, air quality. The government consulted on and published plans to meet its obligations under the Directive. However, ClientEarth argued, through litigation before UK and European courts, that these plans were inadequate.

The judgment of November 2016 was the second time in 18 months that a UK court had agreed with ClientEarth’s view. On 29 April 2015 the Supreme Court ordered that the government revisit its plans in relation to the Air Quality Directive. The November 2016 ruling held that the government’s revised plan – drawn up in light of that earlier judgment – was also inadequate.